GPS开发惯用方法 和用Criteria确定android location providerGPS开发常用方法

GPS开发常用方法 和用Criteria确定android location providerGPS开发常用方法
GPS常用方法总结

取得LocationProvider

public void getLocationProvider()   {     try     {       Criteria mCriteria01 = new Criteria();       mCriteria01.setAccuracy(Criteria.ACCURACY_FINE);       mCriteria01.setAltitudeRequired(false);       mCriteria01.setBearingRequired(false);       mCriteria01.setCostAllowed(true);       mCriteria01.setPowerRequirement(Criteria.POWER_LOW);       strLocationProvider =        mLocationManager01.getBestProvider(mCriteria01, true);              mLocation01 = mLocationManager01.getLastKnownLocation       (strLocationProvider);     }     catch(Exception e)     {       mTextView01.setText(e.toString());       e.printStackTrace();     }   } 

获取经纬度，并返回GeoPoint对象

private GeoPoint getGeoByLocation(Location location)  {    GeoPoint gp = null;    try    {      /* 当Location存在 */      if (location != null)      {        double geoLatitude = location.getLatitude()*1E6;        double geoLongitude = location.getLongitude()*1E6;        gp = new GeoPoint((int) geoLatitude, (int) geoLongitude);      }    }    catch(Exception e)    {      e.printStackTrace();    }    return gp;  }

将经纬度转换成实际屏幕坐标

Point myScreenCoords = new Point();GeoPoint tmpGeoPoint = new GeoPoint((int)(mLocation.getLatitude()*1E6),(int)(mLocation.getLongitude()*1E6));mapView.getProjection().toPixels(tmpGeoPoint, myScreenCoords);

点击MapView任意一点获得坐标

@Override public boolean onTouchEvent(MotionEvent ev) {     int actionType = ev.getAction();     switch (actionType) {     case MotionEvent.ACTION_UP:                  Projection proj = mapView.getProjection();             GeoPoint loc = proj.fromPixels((int)arg0.getX(), (int)arg0.getY());              String sirina=Double.toString(loc.getLongitudeE6()/1000000);             String dolzina=Double.toString(loc.getLatitudeE6()/1000000);         }      return false;}

经纬度改变来刷新地图

  public void refreshMapView()   {     GeoPoint p = new GeoPoint((int)(dLat* 1E6), (int)(dLng* 1E6));     mMapView01.displayZoomControls(true);    /* 将Map的中点移至GeoPoint */    mMapController01.animateTo(p);     mMapController01.setZoom(intZoomLevel);   } 

根据当前的经纬度，获取相关的一些地址信息

/* 创建Geocoder对象 */        //根据地理环境来确定编码        //注意这个Locale是java.util.Locale包的类,获取当前系统设定的语言        Geocoder gc = new Geocoder        (EX09_05.this, Locale.getDefault());                /* 取出地理坐标经纬度 */        double geoLatitude = (int)gp.getLatitudeE6()/1E6;        double geoLongitude = (int)gp.getLongitudeE6()/1E6;                /* 自经纬度取得地址（可能有多行地址） */        List<Address> lstAddress =         gc.getFromLocation(geoLatitude, geoLongitude, 1);                StringBuilder sb = new StringBuilder();                /* 判断地址是否为多行 */        if (lstAddress.size() > 0)        {          Address adsLocation = lstAddress.get(0);          for(int i=0;i<adsLocation.getMaxAddressLineIndex();i++)          {            sb.append(adsLocation.getAddressLine(i)).append("\n");          }          sb.append(adsLocation.getLocality()).append("\n");          sb.append(adsLocation.getPostalCode()).append("\n");          sb.append(adsLocation.getCountryName());        }        

根据输入地址，取得其GeoPoint对象

  private GeoPoint getGeoByAddress(String strSearchAddress)   {     GeoPoint gp = null;     try     {       if(strSearchAddress!="")       {         Geocoder mGeocoder01 = new Geocoder         (EX09_07.this, Locale.getDefault());                  List<Address> lstAddress = mGeocoder01.getFromLocationName                           (strSearchAddress, 1);        if (!lstAddress.isEmpty())         {           Address adsLocation = lstAddress.get(0);           double geoLatitude = adsLocation.getLatitude()*1E6;           double geoLongitude = adsLocation.getLongitude()*1E6;           gp = new GeoPoint((int) geoLatitude, (int) geoLongitude);         }       }     }     catch (Exception e)     {        e.printStackTrace();      }     return gp;   } 

地图放大缩小按钮

 /* 放大Map的Button */    mButton02 = (Button)findViewById(R.id.myButton2);     mButton02.setOnClickListener(new Button.OnClickListener()     {            public void onClick(View v)       {         intZoomLevel++;         if(intZoomLevel>mMapView01.getMaxZoomLevel())         {           intZoomLevel = mMapView01.getMaxZoomLevel();         }         mMapController01.setZoom(intZoomLevel);       }     });          /* 缩小Map的Button */    mButton03 = (Button)findViewById(R.id.myButton3);     mButton03.setOnClickListener(new Button.OnClickListener()     {              public void onClick(View v)       {         intZoomLevel--;         if(intZoomLevel<1)         {           intZoomLevel = 1;         }         mMapController01.setZoom(intZoomLevel);       }     });

以下文章转载：http://marshal.easymorse.com/archives/2528
android location provider有两个：

    * LocationManager.GPS_PROVIDER：GPS，精度比较高，但是慢而且消耗电力，而且可能因为天气原因或者障碍物而无法获取卫星信息，另外设备可能没有GPS模块；
    * LocationManager.NETWORK_PROVIDER：通过网络获取定位信息，精度低，耗电少，获取信息速度较快，不依赖GPS模块。

为了程序的通用性，希望动态选择location provider。对android通过Location API显示地址信息做了个别改动，可以看到使用了gps定位，精度较高：



这里使用到了Criteria，可根据当前设备情况自动选择哪种location provider。见

LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);Criteria criteria = new Criteria();criteria.setAccuracy(Criteria.ACCURACY_FINE);// 设置为最大精度criteria.setAltitudeRequired(false);//不要求海拔信息criteria.setBearingRequired(false);// 不要求方位信息criteria.setCostAllowed(true);//是否允许付费criteria.setPowerRequirement(Criteria.POWER_LOW);// 对电量的要求location = locationManager        .getLastKnownLocation(locationManager.getBestProvider(criteria, true));

原来的写法很简单：

LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);location=locationManager.getLastKnownLocation(LocationManager.NETWORK